Ceramic fuses, What are they worth to ya? Options

[914Wes]

I found a stash of ceramic fuses in 8, 16, and 25 amp. About 2-300 of each are available. I was wondering what do you guys figure spare fuses are worth now that they are not being made in ceramic anymore. How would you guys like to purchase spares? I could make them into complete set of 12 for the fuse panel, 1 of each needed depending on year, or perhaps just small 5 packs like the 911 did it with 3 x 8 amp fuses, 1x 16 amp, 1 x 25 amp? Obviously not trying to do this to get rich but would need to make it worth my time to repack/ship fuses.

[bdstone914]

I have in an emergency wrapped a burned out fuse in aluminum foil to get going.

[Spoke]

I have in an emergency wrapped a burned out fuse in aluminum foil to get going.

Now there's a guy with his feet on the ground. (IMG:style_emoticons/default/beerchug.gif)

I'm missing the point of using ceramic fuses. I drive my 914 all the time and can't remember the last time I had to replace a burned fuse.

[914Wes]

I have in an emergency wrapped a burned out fuse in aluminum foil to get going.

Now there's a guy with his feet on the ground. (IMG:style_emoticons/default/beerchug.gif)

I'm missing the point of using ceramic fuses. I drive my 914 all the time and can't remember the last time I had to replace a burned fuse.

If you read the details they are plastic fuses offered for cheap. They often melt and lead to issues and often have a cheap aluminum conductor. I would be offering NOS fuses from 70s.

[JamesM]

Now there's a guy with his feet on the ground. (IMG:style_emoticons/default/beerchug.gif)

I'm missing the point of using ceramic fuses. I drive my 914 all the time and can't remember the last time I had to replace a burned fuse.

If you read the details they are plastic fuses offered for cheap. They often melt and lead to issues and often have a cheap aluminum conductor. I would be offering NOS fuses from 70s.

I guess im still confused as well?

https://memotronics.com/5-fuses-bullet-cera...losser-germany/

https://www.napaonline.com/en/p/ATMN171214?...ppid=ATMN171211



Littlefuse datasheets for their GBC fuses list them as being ceramic/heat resistant bodies as well?

https://www.littelfuse.com/products/fuses-o...ducts-fuses/gbc

[wonkipop]

Now there's a guy with his feet on the ground. (IMG:style_emoticons/default/beerchug.gif)

I'm missing the point of using ceramic fuses. I drive my 914 all the time and can't remember the last time I had to replace a burned fuse.

If you read the details they are plastic fuses offered for cheap. They often melt and lead to issues and often have a cheap aluminum conductor. I would be offering NOS fuses from 70s.

I guess im still confused as well?

https://memotronics.com/5-fuses-bullet-cera...losser-germany/

https://www.napaonline.com/en/p/ATMN171214?...ppid=ATMN171211



Littlefuse datasheets for their GBC fuses list them as being ceramic/heat resistant bodies as well?

https://www.littelfuse.com/products/fuses-o...ducts-fuses/gbc

first link looks interesting. do appear to be ceramic.
my guess - older stock.
or could even be an older image - but you buy em and plastic turns up.
the big giveaway on the ceramic fuses is that the red ones in particular are a dark red when ceramic. the thermoplastic are a much brighter less dark red. the whites also look a starker white when plastic.

probably worth getting a pack from that first link to see what happens.

a lot of advertisers have older images, but the stock they are selling is whats available now. which is not ceramic body and does not have brass/copper filament.

look closer at little fuse datasheets. just says heat resistant body. doesn't say ceramic.
all the plastic body fuses are marketed as heat resistant thermoplastic. maybe some are. some are definitely not. picture on data sheet seems to show aluminium filament.
i suspect those fuses are the newer stock and a bit inferior.

[JamesM]

look closer at little fuse datasheets. just says heat resistant body. doesn't say ceramic.
all the plastic body fuses are marketed as heat resistant thermoplastic. maybe some are. some are definitely not. picture on data sheet seems to show aluminium filament.
i suspect those fuses are the newer stock and a bit inferior.

Littlefuse calls them ceramic in their product description for them so (IMG:style_emoticons/default/confused24.gif)

Objectively, what makes a fuse inferior anyways? Popping before its supposed to? Not popping when its supposed to?

Its a fuse, they are not to complicated. Ceramic or not if its getting hot enough to melt anything without popping an 8 amp fuse I suspect you have other issues/high resistance at connections adjacent to the fuse itself.

[wonkipop]

look closer at little fuse datasheets. just says heat resistant body. doesn't say ceramic.
all the plastic body fuses are marketed as heat resistant thermoplastic. maybe some are. some are definitely not. picture on data sheet seems to show aluminium filament.
i suspect those fuses are the newer stock and a bit inferior.

Littlefuse calls them ceramic in their product description for them so (IMG:style_emoticons/default/confused24.gif)

Objectively, what makes a fuse inferior anyways? Popping before its supposed to? Not popping when its supposed to?

Its a fuse, they are not to complicated. Ceramic or not if its getting hot enough to melt anything without popping an 8 amp fuse I suspect you have other issues/high resistance at connections adjacent to the fuse itself.

not popping when its supposed to.


-----

some of the heat that is supposed to go into severing the filament is absorbed by the core described loosely as heat resistant thermoplastic. delays the fuse breaking.
fuse hangs on. damage to components or wiring the fuse is designed to protect occurs.
best case scenario is plastic fuse distorts and drops out of holders. worst case it stays in there and plastic keeps absorbing heat while filament maintains integrity.

ceramic is more than heat resistant. its an extremely good insulator and non conductor.
in this application i wouid go so far as to describe it as inert.

you are correct. the fuses are remarkably simple - in original form and in original materials. i would not be so confident describing the copy as being as simple.

[JamesM]

not popping when its supposed to.

Then that would be a real problem if what they are selling as an 8amp fuse isn't actually an 8amp fuse.

I would be somewhat surprised if that is the case with the littlefuse part given fuses are sort of their thing. Cheap Chinese knockoffs not so much as their thing is making parts that look sort of like an original part but don't actually do anything.

It would be worth some real testing to see what current the plastic fuses pop at, but I still suspect anyone melting anything has other electrical issues. Specifically resistance at the connections around the fuse (either the fuse terminal or the spade connector) being higher than the resistance of the fuse element causing heat to be generated outside the fuse element and transferring to the body. Yes a proper ceramic fuse would be added insurance against this, but that doesn't fix the underlying issue.


This is all just assumption though, someone would need to actually test the fuse to know.

Two things:

1. Run more than 8 amps through one to see if (and at what amperage) it pops.

2. Run less than 8 amps though it for an extended period and see if it melts.

If those 2 pass than anyone melting fuses in their car has other issues and popping in a ceramic fuse just means they are more likely to melt their wire insulation instead.

I have some of the littlefuse parts coming to the shop. while I don't have a way to accurately load test them at the moment ill check out the fuse bodies and see what sort of heat they take.